With the development of the communication technology, video contents are often provided to users by transmitting video contents through a wired or wireless network or a satellite.
During the transmission of video contents, transmission errors may occur due to various causes. The error concealment (EC) technique has been introduced to detect and to correct such transmission errors. The EC technique may improve the quality of the transmitted video contents.
The error concealment (EC) technique may be classified into a forward error correction (FEC) and a backward error correction (BEC).
In the forward error correction, a reception device detects an error and recovers the detected error. When transmitting video contents, a redundant bit is added to the video contents in order to correct such transmission error.
In the backward error correction, if an error is detected in transmitted video contents, a reception device notifies the occurrence of the error in the video contents to a transmission device. In response to such notification, the transmission device retransmits the video contents and the reception device recovers the error video contents based on the retransmitted video contents. This backward error correction is used in most data communications.
In a related technology, the forward error correction or the backward error correction has been used to detect and recover an error in a video. In particular, spatial interpolation scheme has been used to detect and recover an error in a video.
In the technology using the spatial interpolation scheme, a reception device recovers pixel information of a lost block by using information of blocks positioned near the lost block and correctly received from a transmission device. Such recovered video, however, often includes blurring that can be easily acknowledged by a viewer. The quality of the recovered video is unsatisfactory.
Furthermore, a data hiding technique has been introduced to recover an error in a video (e.g., video images transported as an encoded video stream in accordance with an MPEG standard).
In the typical data hiding technique, a transmission device extracts description information from the video by using a discrete cosine transform (DCT). Such description information may be representative information of the video. The transmission device inserts the extracted description information into an original image and transmits the video with the inserted description information to a reception device. When a reception device detects an error in the received video contents, the reception device extracts the description information from the received video contents and recovers the video by correcting the detected errors based on the extracted description information.
When an error is recovered by using the typical hidden data technique, discontinuity between blocks may occur in the recovered video. Accordingly, a recovery performance of such typical hidden data technique is poor, especially, recovering images in an edge area and in a texture area.